Bioengineering triacetic acid lactone production in Yarrowia lipolytica for pogostone synthesis.

Yarrowia lipolytica is an oleaginous yeast that is recognized for its ability to accumulate high levels of lipids, which can serve as precursors to biobased fuels and chemicals. Polyketides, such as triacetic acid lactone (TAL), can also serve as a precursor for diverse commodity chemicals. This study used Y. lipolytica as a host organism for the production of TAL via expression of the 2-pyrone synthase gene from Gerbera hybrida. Induction of lipid biosynthesis by nitrogen-limited growth conditions increased TAL titers. We also manipulated basal levels of TAL production using a DNA cut-and-paste transposon to mobilize and integrate multiple copies of the 2-pyrone synthase gene. Strain modifications and batch fermentation in nitrogen-limited medium yielded TAL titers of 2.6 g/L. Furthermore, we show that minimal medium allows TAL to be readily concentrated at >94% purity and converted at 96% yield to pogostone, a valuable antibiotic. Modifications of this reaction scheme yielded diverse related compounds. Thus, oleaginous organisms have the potential to be flexible microbial biofactories capable of economical synthesis of platform chemicals and the generation of industrially relevant molecules.

Practical and scalable synthesis of beclomethasone dipropionate.

Beclomethasone dipropionate (1) is a synthetic corticosteroid with anti-inflammatory, antipruritic, and anti-allergy properties. It is widely used to treat asthma, allergic rhinitis, and dermatoses. However, existing synthetic routes to this active pharmaceutical ingredient (API) contain steps resulting in low and/or inconsistent yields, and use obsolete reagents. Such inconsistencies coupled with a lack of reliable experimental data makes laboratory-scale and large-scale synthesis of this API difficult and time-consuming. In this paper, we report a practical and scalable approach to synthesize 1 from the readily available steroidal intermediate, 16ß-methyl epoxide (3, DB-11). A gram-scale to kilogram-scale synthesis of 1 was achieved with 82% yield, using a cost-effective and scalable methodology. Selective propionylation of the hydroxyl groups at C17 and C21 demonstrate the fact that this approach can be conveniently implemented in fine chemical industries.

Updating Levothyroxine Synthesis for the Modern Age.

Synthesis of levothyroxine sodium, the sodium salt of a synthetic levoisomer of thyroxine, revolutionized the management of hypothyroidism and related symptoms. However, the primary synthetic route to this active pharmaceutical ingredient (API) is more than 70+ years old with low-yielding steps and obsolete reagents. It lacks experimental data on intermediates, making laboratory and large-scale synthesis of this API difficult and time-consuming. Here, we describe an improved synthesis of levothyroxine using commonly available modern reagents. By modifying and replacing low yielding and/or unproductive steps of Chalmers synthesis, we were able to achieve higher overall yields (39-51%) consistently. Key modifications include an alternative path to the selective N-acetylation step that yielded 5 in a pure and consistent fashion. Our improved methodology, coupled with detailed experimental data, provides a practical alternative to existing methods that can be conveniently implemented to synthesize Levothyroxine sodium in fine chemical settings.

An efficient and high-yielding method for extraction and purification of linamarin from Cassava; in vitro biological evaluation.

During the last three decades, studies of linamarin extracted from cassava have received increased attention due to the presence of high cyanogenic compounds in these extracts. The methods that are utilized to isolate linamarin are either tedious or use acidic conditions resulting in poor yields. In this study, a novel cryocooled method of extraction has been developed to isolate linamarin from Cassava root peel. Approximately 18 g of linamarin was isolated from 1 kg of fresh Cassava root peel, which is the highest amount reported to date. Linamarin was fully characterized using NMR, IR and LCMS. The anti-cancer properties of pure linamarin and Cassava crude extract were evaluated by a comprehensive cytotoxic assay, using MCF-7, HepG2, NCI H-292, AN3CA and MRC-5 cell lines. The crude extract showed higher cytotoxicity compared to pure linamarin. The results of the biological evaluation are comparable to other reported studies in the literature.